In the field of the inspection of aeronautical parts, and notably of stiffeners, it is known practice to use an ultrasound sensor to perform a manual non-destructive inspection of the state of material health of the stiffeners mounted on an aircraft structure. The sensor sends ultrasound signals toward the stiffener. These ultrasound signals are transmitted through said stiffener and reflected by the different interfaces passed through. The flight time and the amplitude of the ultrasound signal received give information on the material health of the part.
Generally, the ultrasound sensor is mounted at the end of a handle displaced manually by an operator. This ultrasound sensor is linked to a display screen which displays the image of the state of internal health of the stiffener as the ultrasound sensor is displaced. Thus, the image displayed on the screen scrolls as the operator displaces the ultrasound sensor along the stiffener.
Such an operation is generally restrictive because it requires great at tention on the part of the operator who has to displace the ultrasound sensor while ensuring that the latter is indeed in contact with the surface of the stiffener and who must, at the same time, view the display screen to check the state of the inspected area of the stiffener. This operation requires the operator to be qualified, which results in a relatively high labor cost.
Furthermore, this method involves an inspection of the state of internal health of the stiffener, stiffener by stiffener. Given the number of stiffeners mounted on each aircraft structure, it will be understood that the complete inspection of all the stiffeners of a structure is lengthy and tedious.
Furthermore, since the operator has to be able to access the stiffener and follow the stiffener over its entire length, only open structures can be inspected, that is to say planar structures or structures that have easy accessibility for the operator. Thus, only panels of structures can be inspected. The closed structures, such as the caissons, for which there are only small lateral openings, cannot be inspected by the conventional method. Now, with the arrival on the market of aircraft produced largely in composite materials, more and more closed structures are manufactured in composite materials with stiffeners distributed over the internal wall of these structures.
There is therefore a real need for an automatic ultrasound inspection device which can be displaced independently along stiffeners of the structures made of composite materials, regardless of the form of the structure (closed or open).